User is unable to scroll to Sign In button on mobile device if there are more categories.

[dpatil-magento]

Description:
Mobile specific: When there are more categories user cant scroll to Sign in button. It blocks user from signing to the account.

Steps to reproduce the behavior:

1. Create more categories which should cross length of mobile device around 8-10. (For iphone SE its 8 or greater).
2. On Venia storefront open Main menu Left drawer and try to scroll to Sign In button.

Expected behavior:
Either user should be allowed to scroll to Sign-in button or the Sign-in button should be always visible at bottom and user should be able scroll the categories.

Actual :
User is unable to scroll to Sign-in button, also it tough to scroll to last category (PFA screen).

Note - Works fine on browser.

Screen:
Mobile -

Browser -

[dpatil-magento]

Its now happening on Shipping Address section also.

[awilcoxa]

duplicate of #1071